Rumors are circulating that the steamy sex scene in Factory Girl wasn’t actually two actors perfecting their craft, but it was actually the real thing. According to The New York Daily News, Sienna Miller and Hayden Christensen were so hot for each other during the filming that they got worked up and went all the way.

“It’s not simulated,” an insider tells us. “They’re really doing it.”It was during the film’s
Louisiana shoot that Miller ran into another squall in her stormy romance with Jude Law – and turned for comfort to Christensen, the “Star Wars” heartthrob.“They spent about a month hanging out,” says one pal of Christensen. “But then she decided she didn’t want a relationship. Hayden was devastated. He really fell for her.”

Added a friend of Miller, “Sienna wanted to try to make another go of it with Jude. But, again, it didn’t work out. At the end of last summer, she and Hayden ended up in
Toronto for more shooting. They hadn’t talked in six months. But it turned out to be a great reunion.”

At the movie’s premiere on Monday, director George Hickenlooper would tell us only: “Sienna and Hayden grew close during the filming. It was an emotional experience for all of us.” As for the sex, he said, “We tried to portray it tastefully.”